Filter-leaf construction



Dec. 30, 1930.

w. H. BACHELDOR FILTER LEAF CONSTRUCTION Filgd Aug. 5, 1929 frzvenz af ZZz'a fiacZe 762073 Patented Dec. 30, 1930 UNITED STATES PATENT OFFICE WILLIAM H. BACHELDOR, OF WOOD RIVER, ILLINOIS, ASSIGNOR TO STANDARD OIL COMPANY, OF WHITING, INDIANA, A CORPORATION OF INDIANA FILTER-LEAF consrnncrron Application filed August 5, 1929. Serial No. 383,635.

This invention relates to filter leaves which are particularly adapted to be employed in filters of the pressure type. a

The invention will be readily understood from the following description of a preferred embodiment thereof in conjunction with the accompanying drawings, in which Figure 1 is an elevational view of the filter leaf, embodying the improvements of the inm vention, with certain partsbroken away to show the construction;

Fig. 2 is an enlarged fragmentary sectional view taken on line 2 of Fig. 1;

Fig. 3 is an enlarged fragmentary sectional View showing the filtrate outlet.

Referrin more particularly to the drawings: The lter leaf is designated as a whole at 10 and comprises a frame 11 constituted of a series of metal bars 12. The bar 112 at the top side of the frame 11 is extended at either end to provide a pair of projections 13 for supporting the frame in its operative position within a filter press. One of the frame bars 12 is provided with a threaded tubular outlet conduit 14 adapted to be connected to a suitable conduit (not shown) which communicates with the exterior of the filter press.

This outlet 14 is preferably located adjacent the lower side of the filter leaf and communicates, with a bore formed in one of the bars 12, as shown by Fig. 3. The donduit 14 may be welded to the bar 12.

A suitable perforate means for supporting the filtering medium is mounted within the frame 11. Such supporting means may comprise the following: A sheet 15 of relatively coarse woven metal wire, for example 4 mesh, is mounted within the frame 10, being secured thereto at its'edges by a series of welds 16. A sheet 17 of finer woven metal wire, for example 10 mesh, is located on either side of the sheet 15, being secured in such position in a manner which will be hereinafter described. A sheet 18 of still finer woven metal wire, for example 35 mesh, overlies each of the sheets 17. These sheets 18 are of sufficient dimension so that they overlap the sides of the filter frame bars 12 in the manner shown by Figs. 1 and 2.

A sheet of filtering medium 19 is applied on each side of the frame 11 so that it overlies'and rests upon the woven wire sheets 19. These filtering sheets 19 are of sufficient dimension so that they overlap the sides of the filter frame bars in a manner similar to the wire sheets 18.

While the invention is not concerned with the use of any specific type of filtering medium, the present embodiment contemplates the use of asbestos cloth.

The wire sheets 18 and the filter sheets 19 are clamped to the frame 11 by metal strips 20 secured in clamping relation, to the sheets 18 and 19 and the frame bars 12, by a plurality of bolts 21. These bolts 21 are passed through corresponding openings in the frame bars 12, the sheets 18 and 19, and the metal clamping strips 20. By means of this structure, upon the bolts 21 having their nuts tightened, none of the material being filtered can pass into the interior of the leaf, except through the filter sheet 19. To insure a tight seal between the filter cloth 19 and the frame bars 12, it may be found necessary to fill the interstices of those portions .of the wire cloth 18 which overlie the frame bars 12 with a suitable sealing medium, such as Key paste.

To provide a channel, within the leaf, for the filtered liquid or filtrate which flows into the leaf, the following structure is employed. Immediately adjacent each sheet of the wire cloth 18, a flat metal strip 22 is secured to the inner faces of each of the frame bars'12. These strips may be welded to the bars 12 and are sloped. inwardly so that their inner edges abut the wire sheets 17. The strips 22 thus function to support the wire sheets 17 within the frame 11. It will be seen that the strips 22 form between them a continuous channel 23 within the leaf, through which channel the filtered I liquids may flow to the outlet conduit 14.

The leaf of the present invention is particularly adapted to be used in pressure filters of the well-known Kelly or Sweetland types. In these types of filters, the leaf is placed within a closed tank or chamber into which is fed the liquid to be filtered. The liquid flows through the filter cloth 19 and into the interior of the leaf, the cloth 19 functioning to filter from the liquid any of the solid matter entrained therein. With the leaf of the present invention, the filter cloth 19 and the wire cloth 18 will tend to be pressed toward the wire cloths 15 and 17 by the flow of the liquid through them.

When this occurs, the filtered liquid or filtrate will pass through the screens 15 and 17 into the channel 23 defined by the metal strips 22, and'out through the conduit 14 to the exterior of the filter. It will be noted that the strips 22 function as breakers so that the cloths 18 and 19 are protected from the sharp edges of the frame bars 12, when they are forced inwardly by the flow of'the liquid through them.

The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations should be construed therefrom, but the appended claims should be construed as broadly as permissible, in view of the prior art.

I claim:

1. A filter press leaf comprising an imperforate frame provided with an enlarged fenestral opening, perforate supporting means carried in said opening, filter media carried by said frame and positioned outside of and adjacent to said perforate supporting means, means positioned adjacent said frame and within the opening therein for spacing a portion of said filter media from said perforate supporting means and thereby forming a continuous liquid channel along said frame and between said perforate supporting means and said filter media, and a liquid outlet conduit communicating with said channel.

2. A filter press leaf comprising an imperforate frame provided with an enlarged fenestral opening, perforate supporting means carried in said opening, filter media carried by said frame and positioned outside of and adjacent to said perforate sup-- porting means, means comprising a plate positioned adjacent said frame within the opening therein and between said perforate supporting means and said filter media for spacing a portion of said filter media from said perforate supporting means thereby forming a liquid channel along said frame and between said perforate supporting means and said filter media, and a continuous liquid outlet conduit communicating with said channel.

between said perforate supporting means and said filter media, and a liquid outlet conduit communicating with said channel.

4. A filter press leaf comprising an imperforate frame provided with an enlarged fenestral opening, perforate supporting means carried in said opening, a sheet of filter cloth positioned across said opening adjacent to, and outside of, said perforate supporting means, means comprising an elongated plate positioned adjacent said frame, within the opening therein, and between said filter cloth and said perforate supporting means, thereby spacing a portion of said filter cloth from said perforate supporting means to form a continuous liquid channel, and a liquid outlet conduit communicating with said channel.

5. A filter press leaf comprising an imperforate frame provided with an enlarged fenestral opening, a sheet of filter cloth on either side of said frame, each sheet covering the opening therein, means comprising a pair of spaced elongated plates, positioned adjacent said frame and within the opening therein, adapted to prevent the portions of the filter cloth adjacent them from being forced inwardly beyond a predetermined point and to form a continuous liquid channel adjacent the frame, and a liquid outlet conduit communicating with said channel,

6. A filter press lea-f comprising an imperforate frame provided with an enlarged fenestral opening, a sheet ofcoarse woven metal positioned in said 0 ening and secured to said frame, a sheet of filter cloth on either side of said frame and covering the opening therein, each sheet being positioned adjacent to said sheet of woven metal, a pair of spaced 7. I

plates secured to the inner sides of said frame and disposed wlthin the opening therein,

said plates being located on either side of said woven metal sheet and interposed beforate frame provided with an enlarged fenestralopening,perforatesupporting means car ried in said openlng, said perforate supporting means being of substantially less thickness than said frame whereby the sides of the frame overhang said supportingmeans, filter media carried by said frame and positioned across the opening therein, said filter media extending over the sides of the frame, means positioned adjacent said frame and between said filter media and said perforate support to prevent the portions of the filter media adjacent said means from being forced inwardly beyond a predetermined point and to form a continuous liquid channel adjacent the, frame, and a liquid outlet conduit communicating with said channel.

WILLIAM H. BAGHELDOR. 

